JP5151275B2 - Fuel cell moisture content estimation system - Google Patents

Description

  The present invention relates to a technique for estimating the amount of water in a fuel cell.

  Conventionally, there is a technique for measuring the amount of water in a fuel cell using a current interruption method (see Patent Document 1).

In addition, in a fuel cell system that calculates the amount of water contained in intake air, the amount of water contained in exhaust gas, and the amount of water generated as a result of power generation by integration, and controls intake air based on the calculation result, current interruption There is a technique for periodically initializing a moisture amount calculated by integration using a moisture amount measured using a method (see Patent Document 2).
JP 2005-166601 A JP 2004-192773 A

  Conventionally, estimating (measuring) the amount of water in the fuel cell that is required to control the fuel cell, such as improving the power generation efficiency of the fuel cell, has been performed. Here, as a method of estimating the amount of water in the fuel cell, a method of integrating the amount of moisture in and out of the fuel cell and the amount generated is employed. However, calculation by integration has a problem that errors accumulate due to continued integration.

  Therefore, in order to eliminate this accumulated error, the moisture content in the fuel cell is calculated based on the measured resistance of the fuel cell, and the accumulated estimated moisture content is periodically reset with the calculated value. The method is adopted. However, the amount of water in the fuel cell and the resistance measured in the fuel cell may not necessarily correspond uniquely, so an inaccurate amount of water is calculated, and resetting cannot solve the error problem There is.

  In view of the above problems, an object of the present invention is to reduce an error in an estimated moisture amount when estimating the moisture amount in a fuel cell.

  In order to solve the above-described problems, the present invention determines whether or not the fuel cell is in a predetermined wet state from the resistance of the fuel cell, and based on this determination result, estimates the water amount by integration and determines the resistance. It is possible to reduce the error of the estimated moisture content by calculating the estimated moisture content by switching the moisture content estimation based on the estimated moisture content.

  Specifically, the present invention relates to a measurement unit that measures the resistance of a fuel cell, and based on the measured resistance, the fuel cell has a resistance corresponding to a water content in a plurality of regions of the fuel cell. Only a region where the change is relatively large is wet, a determination unit that determines whether or not a predetermined wet state, and a calculation unit that calculates an estimated amount of water in the fuel cell, the calculation unit includes: When the determination means determines that the fuel cell is not in the predetermined wet state, the estimated moisture amount is calculated by integrating the amount of moisture in and out of the fuel cell and the generation amount, and the determination means determines the When it is determined that the fuel cell is in the predetermined wet state, the fuel cell moisture amount estimation system calculates the estimated moisture amount based on a measurement result by the measurement means.

  Here, the region in which the resistance change according to the water content is relatively large is generally a region in which the participation in power generation is large. That is, the resistance change according to the water content is larger in the region where the power generation is more involved. For example, in a fuel cell having a membrane electrode assembly, a gas diffusion layer, and a flow path as a water-containing region, the greatest change in resistance according to the water content is a region where only the membrane electrode assembly mainly contains water. This is the case. On the other hand, when the membrane electrode assembly overflows with water and the gas diffusion layer and the flow path are also in a state where a lot of water is contained, the resistance change according to the water content becomes relatively small, or the resistance And the relationship between water content and water content is dilute. In general, in a state where water has overflowed to the flow path, the membrane electrode assembly that is greatly involved in power generation is immersed in water, so even if the amount of water in the flow path changes, the resistance hardly changes.

  For this reason, in the fuel cell moisture content estimation system according to the present invention, since the fuel cell has a relatively large change in resistance according to the moisture content, it can calculate an accurate moisture content based on the resistance (predetermined In the wet state) based on the resistance measured using the AC impedance method, the current interruption method, or the like. When it is determined that the fuel cell is in a predetermined wet state, the calculation means calculates an estimated moisture amount based on the measurement result (resistance).

  On the other hand, when it is not in a predetermined wet state, the change in resistance according to the moisture content is relatively small, or the relationship between resistance and moisture content is sparse, so an accurate moisture content is calculated based on the resistance. I can't do it. For this reason, when it is determined that the fuel cell is not in a predetermined wet state, the calculation means calculates the estimated moisture amount by integrating the amount of moisture in and out of the fuel cell and the generated amount.

  The determining means determines whether or not the fuel cell is in a predetermined wet state by referring to the relationship between the resistance of the fuel cell and the wet region, which is obtained in advance, based on the measured resistance. For example, it is possible to determine whether or not the fuel cell is in a predetermined wet state by comparing the measured resistance with a threshold value prepared in advance.

  Further, in the present invention, when it is determined that the fuel cell is in the predetermined wet state, the calculation means and the measurement result used for the determination, and the fuel in the predetermined wet state measured in advance. The estimated water content may be calculated based on the water content in the battery.

  For example, by referring to a map or a relational expression showing the relationship between the resistance and the amount of moisture, the amount of moisture corresponding to the resistance measured and used for determination can be calculated.

  The fuel cell has a membrane electrode assembly as a region, and the determination means determines whether or not the fuel cell is in a predetermined wet state in which only the membrane electrode assembly is wet, and the calculation is performed. When the means determines that the fuel cell is in the predetermined wet state, the measurement result by the measurement means and the moisture in the fuel cell when only the membrane electrode assembly measured in advance is wet. The estimated water amount may be calculated based on the amount.

  The membrane / electrode assembly is greatly involved in power generation, and the resistance change according to the water content is relatively large. For this reason, a state in which only the membrane electrode assembly is wet is defined as a predetermined wet state. When the membrane electrode assembly is in a predetermined wet state, measurement is performed based on the relationship between the amount of water and resistance in the membrane electrode assembly. It is possible to calculate an accurate amount of moisture from the resistance.

Further, in the present invention, the fuel cell has a membrane electrode assembly and a gas diffusion layer as regions, and the determination means is that the fuel cell is wet only in the membrane electrode assembly and the gas diffusion layer. It is determined whether or not the fuel cell is in a predetermined wet state, and when it is determined that the fuel cell is in the predetermined wet state, the calculation unit and the membrane electrode measured in advance The estimated moisture content may be calculated based on the moisture content in the fuel cell when only the joined body and the gas diffusion layer are wet.

  In addition, the system according to the present invention further includes a water content reduction means for reducing the water content in the fuel cell, and the measurement means measures the resistance of the fuel cell while the water content reduction is being executed. May be.

  Reducing the estimated moisture content by actively reducing the moisture content in the fuel cell by performing a scavenging process, etc., and calculating the estimated moisture content based on the measurement results obtained by the measurement means when a predetermined wet state is reached. Can be done.

  Further, in the present invention, the water content reduction means performs the water content reduction at the end of the operation of the fuel cell, and the calculation means determines that the fuel cell is in the predetermined wet state, The estimated water content may be calculated from the determination until the next start of the fuel cell.

  By reducing the amount of water at the end of the operation of the fuel cell and performing a reset before the next start-up, the fuel cell can be controlled at the next start-up based on the estimated amount of water with less error. In addition, it is good also as resetting the estimated water content by periodically reducing the water content other than at the end.

  According to the present invention, it is possible to reduce an error in the estimated moisture amount when estimating the moisture amount in the fuel cell.

  Embodiments of a fuel cell system including a fuel cell moisture content estimation system according to the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing an outline of the configuration of the fuel cell system in the present embodiment. The fuel cell system includes a fuel cell 10, a gas tank 21 for storing fuel gas, a fuel gas passage 22, a circulation passage 25, a fuel off-gas passage 30, an air blower 51, an oxidizing gas passage 52, and an oxidizing off-gas passage. 53, a measuring device 60, and an electronic control unit (hereinafter referred to as “ECU”) 90. The fuel cell system performs an electrochemical reaction in the fuel cell 10 by the fuel gas supplied from the gas tank 21 through the fuel gas passage 22 and the oxidizing gas supplied from the air blower 51 through the oxidizing gas passage 52. Electric power is generated by advancing.

  A pressure reducing valve 23 and a flow control valve 24 are provided in the fuel gas passage 22. The fuel gas supplied from the gas tank 21 to the fuel cell 10 is reduced to a predetermined pressure by the pressure reducing valve 23, the flow rate is adjusted by the flow rate control valve 24, and supplied to the fuel cell 10 through the fuel gas passage 22. . The fuel gas that has passed through the fuel cell 10 is discharged to the circulation passage 25.

  A circulation pump 26 is provided in the circulation passage 25. The circulation pump 26 can return the fuel gas discharged from the fuel cell 10 to the fuel gas passage 22 and increase the flow rate of hydrogen gas supplied to the fuel cell 10 per unit time.

  A purge valve 31 is provided in the fuel off-gas passage 30. Since the hydrogen gas concentration in the gas decreases due to the circulation of the fuel gas, the purge valve 31 is controlled to discharge the fuel off-gas having a low hydrogen gas concentration from the circulation passage 25 to the fuel off-gas passage 30 and the flow control valve 24. By controlling the above, fuel gas having a high hydrogen gas concentration is supplied from the gas tank 21.

  The measuring device 60 measures the impedance of the fuel cell 10. The measuring device 60 corresponds to the measuring means of the present invention. The impedance measured by the measuring means is sent to the ECU 90.

  In addition to the CPU, the ECU 90 includes a ROM, a RAM, and the like that store various programs and maps to be described later, and controls each element of the entire fuel cell system. The purge valve 31, the pressure reducing valve 23, and the flow rate control valve 24 are controlled to open and close by the ECU 90. These controls are adjusted so that the power generation efficiency of the fuel cell is optimized based on the state of the fuel cell including the estimated amount of water in the fuel cell.

  The ECU 90 determines whether or not the fuel cell 10 is in a predetermined wet state, which will be described later, based on the impedance measured by the measuring device 60, and integrates the moisture balance according to the determination result. Alternatively, an estimated water amount that is an estimated value of the water amount in the fuel cell 10 is calculated using any one of the methods of calculating based on the impedance. That is, the ECU 90 functions as a determination unit 91 corresponding to the determination unit of the present invention and a calculation unit 92 corresponding to the calculation unit of the present invention.

  FIG. 2 is a schematic cross-sectional view of the cells constituting the fuel cell 10 in the present embodiment. The fuel cell 10 is configured by stacking one or a plurality of cells, and includes a cathode side separator 11 having an oxidizing gas channel 16 on the inner surface, a cathode side gas diffusion layer 12, a membrane electrode assembly 13, and an anode side gas diffusion. The anode separator 15 having the layer 14 and the fuel gas flow path 17 on the inner surface is sequentially laminated, and power is generated by causing an electrochemical reaction by the supplied reaction gas to proceed in the membrane electrode assembly 13. The reaction gas is a fuel gas supplied from a fuel tank (not shown) and an oxidizing gas obtained from the outside air and supplied. The oxidizing gas is supplied to the cathode side gas diffusion layer 12, and the fuel gas is supplied to the anode side gas diffusion layer 14.

Next, the relationship between the wet region and the impedance in the fuel cell 10 will be described. FIG. 3 is a graph showing the relationship between the moisture content and the impedance in the entire fuel cell 10 according to the present embodiment. In the graph, the horizontal axis represents the moisture content Q _{FC in the} entire fuel cell 10, and the vertical axis represents the impedance R _FC corresponding to the moisture content Q _FC .

  The range indicated by the symbol A (hereinafter referred to as “range A”) in the graph is a range corresponding to the case where the region mainly containing water is only the membrane electrode assembly 13. That is, the range A is a range indicating a change in the amount of moisture in the membrane electrode assembly 13 where power is actually generated, and the amount of change in impedance with respect to the amount of change in moisture is large.

  Further, the range indicated by the symbol B (range B) is a range corresponding to the case where the range mainly containing water is the membrane electrode assembly 13 and the gas diffusion layers 12 and 14. That is, the range B is a range showing a change in the amount of moisture in a state where water has already overflowed from the membrane electrode assembly 13 and the water-containing region has spread to the gas diffusion layers 12 and 14. The amount of change in impedance relative to the amount of change in amount is small.

  The range indicated by the symbol C (range C) is a range corresponding to the case where the range mainly containing water is the membrane electrode assembly 13, the gas diffusion layers 12 and 14, and the flow paths 16 and 17. That is, the range C is a range showing a change in the amount of moisture in a state in which moisture overflows from the gas diffusion layers 12 and 14 and the water-containing region reaches the channels 16 and 17. In this case, since the membrane electrode assembly 13 and the gas diffusion layers 12 and 14 that are directly related to the impedance are in a water-immersed state, even if the entire water amount changes, the impedance hardly changes.

Here, with reference to FIG. 2 and FIG. 3, a wet state determination process and an estimated moisture amount calculation process performed by the ECU 90 will be described. First, the ECU 90 compares the measured impedance with R _FC1 (see FIG. 3). When the measured impedance is larger than R _FC1 , the moisture content is smaller than Q _{FC1 as} shown in the relationship between the impedance and the moisture content shown by the graph in FIG. 3 (see range A in FIG. 3). This means that the range mainly containing water is only the membrane electrode assembly 13 at the time when the impedance is measured.

In other words, the ECU 90 can determine to which region the range including mainly water in the fuel cell 10 has reached by comparing the measured impedance and R _FC1 . In the present embodiment, a state (range A) in which the region mainly containing water is only the membrane electrode assembly 13 is defined as a “predetermined wet state”.

As described above, when the region mainly containing water is only the membrane electrode assembly 13, the amount of change in impedance with respect to the amount of change in water content is large. For this reason, when it is determined that the fuel cell 10 is in the predetermined wet state, the ECU 90 is based on the relationship between the measured impedance and the amount of water in the fuel cell 10 in the predetermined wet state that is measured in advance. By calculating the estimated moisture content, an accurate estimated moisture content can be obtained. More specifically, a method of referring to a map (relationship between impedance and water content in range A in FIG. 3) having a relationship between impedance and water content in a predetermined wet state, or a predetermined wet state The estimated water amount is calculated using a method such as a method using a relational expression representing the relationship between the impedance and the water amount in the method, a method of setting the water amount corresponding to the impedance to a fixed value such as _{QFC1, and the} like.

When the measured impedance is R _FC1 or less, that is, when a region mainly containing water exists in addition to the membrane electrode assembly 13, the amount of change in impedance with respect to the amount of change in moisture is small (range in FIG. 3). See B and C). For this reason, when it is determined that the fuel cell 10 is not in a predetermined wet state, the ECU 90 calculates an estimated moisture amount by integrating the amount of moisture in and out of the fuel cell 10 and the generated amount. The amount of water in the fuel cell 10 mainly includes the moisture taken into the fuel cell 10 together with the oxidizing gas, the moisture discharged together with the oxidizing off gas, the moisture taken into the fuel cell 10 together with the fuel gas, and the fuel off gas. It increases or decreases depending on the moisture that is discharged and the moisture that is generated as a result of power generation. Therefore, ECU 90 is per unit time, the amount of water q _Airin to be incorporated into the fuel cell 10 together with the oxidizing gas, water content q _AirOut, water content q being taken into the fuel cell 10 together with the fuel gas discharged together with the oxidizing off _H2In , the amount of moisture q _H2Out discharged together with the fuel off-gas, and the amount of moisture q _Gen generated along with power generation are calculated, and the sum of these is calculated to calculate the moisture balance per unit time. Then, ECU 90, by integrating the amount of water balance per unit time over time to calculate the estimated water content Q _FC in the fuel cell 10.

  Here, it is preferable that a method suitable for the embodiment is adopted as a method of acquiring the amount of water taken in per unit time and the amount of water discharged. For example, a flow rate measurement device, a temperature measurement device, and a humidity measurement device (not shown) are provided in the gas path, and the flow rate, temperature, and humidity of the taken-in reaction gas and exhausted off-gas are measured, and the ECU 90 is based on these measurement results. There is a method for calculating the amount of water per unit time.

In addition to the above method, the moisture content q _AirIn contained in the oxidant gas taken in is fixed (
For example, a method of 0), a method of _{setting the} amount of water q _AirOut contained in the exhausted oxidizing off gas to a saturated water vapor amount, a method of calculating from the operating state of the fuel cell 10 using a map prepared in advance, humidification When there is a module, there is a method of calculating using a water exchange rate map prepared in advance. As a unit of moisture amount per unit time, for example, gram / second is used.

As a method for obtaining the amount of water q _Gen generated with power generation per unit time, the amount of water generated in advance prepared based on the operating state of the fuel cell 10 including the supply amount of oxidizing gas and fuel gas. There is a method of calculating using the map. However, the method for obtaining the amount of generated water is not limited to the above method, and a method suitable for the embodiment is preferably employed.

ECU90 is this way is obtained, the water content q _Airin to be incorporated into the fuel cell 10 together with the oxidizing gas, water content q _AirOut discharged together with the oxidizing off gas, water content q to be incorporated into the fuel cell 10 with fuel gas _H2In , the amount of water q _H2Out discharged together with the fuel off-gas, and the amount of water q _Gen generated with power generation are integrated over time (for example, refer to the following equation) to calculate the estimated amount of water.
Q _FC = ∫ (q _Gen + q _AirIn + q _H2In −q _AirOut −q _H2Out ) dt

  Next, the flow of processing in this embodiment will be described. FIG. 4 is a flowchart showing the flow of the fuel cell moisture content estimation process in the present embodiment. The process shown in this flowchart is started when the operation of the fuel cell 10 is started, and then repeatedly executed until the fuel cell 10 finishes the operation.

  In step S101, the impedance is measured. The measuring device 60 measures the impedance of the fuel cell 10 during power generation using the alternating current impedance method, and outputs the measurement result to the ECU 90. Thereafter, the process proceeds to step S102.

In step S102, it is determined whether or not the fuel cell 10 is in a predetermined wet state. The ECU 90 receives the impedance measured in step S101 and compares this impedance with R _FC1 (see FIG. 3) to determine whether or not the fuel cell 10 is in a predetermined wet state. In the present embodiment, the ECU 90 determines that the fuel cell 10 is in a predetermined wet state when the measured impedance is greater than R _FC1 . Fuel cell 1
If it is determined that 0 is in the predetermined wet state, the process proceeds to step S103. The ECU 90 determines that the fuel cell 10 is not in a predetermined wet state when the measured impedance is R _FC1 or less. If it is determined that the fuel cell 10 is not in a predetermined wet state, the process proceeds to step S104.

In step S103, an estimated moisture amount is calculated based on the measured impedance. The ECU 90 calculates an estimated moisture amount corresponding to the impedance measured in step S101 by referring to a map prepared in advance stored in a storage device (not shown). The map used here is a map having a correspondence relationship between the impedance and the amount of moisture in the range A in the graph shown in FIG. In the present embodiment, the calculation is performed using the map. However, as described above, a calculation method other than referring to the map may be employed. For example, a method using a relational expression (approximate straight line or the like) indicating a correspondence relationship, or a fixed value (eg _QFC1 )
The method determined in (1) may be adopted. Thereafter, the process proceeds to step S101.

  In step S104, the estimated moisture amount is calculated by integration. The ECU 90 calculates the estimated moisture amount by integrating the balance of the moisture amount per unit time. The ECU 90 per unit time includes the amount of moisture taken into the fuel cell 10 together with the oxidizing gas, the amount of moisture discharged together with the oxidizing off gas, the amount of moisture taken into the fuel cell 10 together with the fuel gas, and the moisture discharged together with the fuel off gas. The amount of water and the amount of water generated with power generation are calculated, and the sum of these is calculated to calculate the balance of the amount of water per unit time. Then, the ECU 90 calculates the estimated moisture amount in the fuel cell 10 by integrating the moisture balance per unit time. Thereafter, the process proceeds to step S101.

That is, according to the present embodiment, it is determined whether or not the fuel cell 10 is in a predetermined wet state from the impedance, and based on this determination result, the moisture amount estimation based on the integration and the moisture amount estimation based on the impedance are performed. By calculating the estimated moisture amount by switching, the error of the estimated moisture amount can be reduced. In addition, since an estimated moisture amount with less error is obtained, the fuel cell can be more effectively controlled based on the estimated moisture amount.

In the above-described embodiment, a state where only the membrane electrode assembly 13 is wet is defined as a predetermined wet state, and the fuel cell is in the predetermined wet state when the measured impedance is larger than R _FC1. However, when only the membrane electrode assembly 13 and the gas diffusion layers 12 and 14 are wet, a predetermined wet state is defined, and when the measured impedance is larger than _RFC2 , the fuel cell You may judge that it exists in a predetermined wet state.

When the wet state is determined based on R _FC2 , a map, a relational expression, or a fixed value indicating the relationship between the impedance and the moisture amount in the ranges A and B in FIG. 3 is used for calculating the estimated moisture amount based on the impedance. A value or the like is used.

In addition, the amount of water in the fuel cell 10 is reduced by scavenging before the operation of the fuel cell 10 is completed, and the estimated amount of water is calculated based on the measured impedance when the fuel cell 10 reaches a predetermined wet state. Thus, the estimated water content may be reset. In this case, the ECU 90 monitors the measurement result by the measuring device 60 during scavenging, and detects that the impedance exceeds R _FC1 , that is, the region containing mainly water is only the membrane electrode assembly 13. The estimated moisture amount is reset with a value calculated based on the measured impedance. For the calculation of the estimated moisture amount based on the measured impedance, a method suitable for the embodiment, such as a map reference method, a relational expression method, a fixed value method, or the like may be employed, as in the above-described embodiment. Note that the timing at which the reset is performed may be before the end of the operation of the fuel cell 10 or may be at the next startup.

As the end scavenging, there are end scavenging for reducing the amount of water in the fuel cell 10 for activation below the freezing point, end scavenging performed at the normal end, and the like. In the scavenging at the end for starting below the freezing point, it is preferable to set the threshold value for determining a predetermined wet state to R _FC1 in order to prevent the water in the fuel cell 10 from freezing. In the end scavenging, a threshold value for determining a predetermined wet state may be _RFC2 .

  In this way, by performing scavenging before the end of the operation, it is possible to control the operation of the fuel cell based on a more accurate estimated moisture amount at the start of the next operation. In addition, it is good also as resetting an estimated water | moisture content regularly by scavenging regularly separately from the time of completion | finish of a driving | operation.

  Further, even in a state where impedance measurement cannot be performed, such as a state where the fuel cell 10 is not generating power, it is considered that the fuel cell is in a predetermined wet state by performing a predetermined (for example, a fixed time) scavenging. The estimated moisture content can be reset. By doing in this way, even in the situation where impedance cannot be measured, the estimated moisture amount can be reset and the error can be eliminated.

It is the figure which showed the outline of the structure of the fuel cell system in embodiment. It is a schematic sectional drawing of the cell which comprises the fuel cell in embodiment. It is a graph which shows the relationship between the moisture content and the impedance in the whole fuel cell which concerns on embodiment. It is a flowchart which shows the flow of the moisture content in a fuel cell in embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fuel cell 11 Cathode side separator 12 Cathode side gas diffusion layer 13 Membrane electrode assembly 14 Anode side gas diffusion layer 15 Anode side separator 16 Oxidation gas flow path 17 Fuel gas flow path 21 Gas tank 51 Air blower 60 Measuring device 90 Electronic control unit (ECU)
91 Determination unit 92 Calculation unit

Claims (6)

A measuring means for measuring the resistance of the fuel cell;
Based on the measured resistance, whether the fuel cell is in a predetermined wet state in which only a region where the change in resistance according to the water content is relatively large is wet among a plurality of regions of the fuel cell. Determining means for determining whether or not;
Based on the determination result by the determination means, comprising: a calculation means for calculating an estimated moisture amount in the fuel cell by switching between a moisture amount estimation based on integration and a moisture amount estimation based on resistance ;
The calculating means includes
When it is determined by the determination means that the fuel cell is not in the predetermined wet state, the estimated moisture amount is calculated by integrating the moisture input / output amount and the generated amount in the fuel cell as the moisture amount estimation by the integration. And
When the determination unit determines that the fuel cell is in the predetermined wet state, the estimated moisture amount is calculated based on a measurement result by the measurement unit as a moisture amount estimation based on the resistance .
Fuel cell moisture content estimation system. When it is determined that the fuel cell is in the predetermined wet state, the calculation means includes a measurement result used for the determination, and a moisture amount in the fuel cell in the predetermined wet state measured in advance. Calculating the estimated moisture content based on
The fuel cell moisture content estimation system according to claim 1. The fuel cell has a membrane electrode assembly as a region,
The determination means determines whether or not the fuel cell is in a predetermined wet state in which only the membrane electrode assembly is wet;
When it is determined that the fuel cell is in the predetermined wet state, the calculation means includes a measurement result obtained by the measurement means, and the inside of the fuel cell when only the membrane electrode assembly measured in advance is wet. And calculating the estimated water content based on the water content of
The fuel cell moisture content estimation system according to claim 2. The fuel cell has a membrane electrode assembly and a gas diffusion layer as regions,
The determination means determines whether or not the fuel cell is in a predetermined wet state in which only the membrane electrode assembly and the gas diffusion layer are wet;
In the case where it is determined that the fuel cell is in the predetermined wet state, the calculation means, when the measurement result by the measurement means, and only the membrane electrode assembly and the gas diffusion layer measured in advance are wet Calculating the estimated moisture content based on the moisture content in the fuel cell of
The fuel cell moisture content estimation system according to claim 2. Further comprising water content reducing means for reducing the water content in the fuel cell;
The measuring means measures the resistance of the fuel cell while the water content reduction is being performed;
The fuel cell moisture content estimation system according to any one of claims 1 to 4. The moisture content reducing means performs the moisture content reduction at the end of operation of the fuel cell,
When it is determined that the fuel cell is in the predetermined wet state, the calculation means calculates the estimated moisture amount from the determination to the next startup of the fuel cell.
The fuel cell moisture content estimation system according to claim 5.

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